Numerical study of the density ratio effect on propagation of a cloud of hot electrons

Summary form only given. A study is made of the formation of the spectra of Langmuir waves excited as a result of the development of beam-plasma instability in a collisionless plasma with low-frequency turbulence. The effects of density ratio on evolution of propagation of beam and excited Lnagmiur waves is investigated in one dimensional solar corona plasma with numerical calculations of quasilinear equations. We performed numerical computations of the beam dynamics for a wide range of initial beam number density. It is found that the character of the stream diffusion and of the plasma turbulence growth greatly depend on the stream density. Results of numerical simulations show that the electron distribution function relaxes to a plateau state and evolution of the height of the plateau is investigated and the dependence of the these results on the stream density is obtained.